Publications

• A new subfamily of short bacterial adenylate kinases with the Mycobacterium tuberculosis enzyme as a model: a predictive and experimental study.

  Munier-Lehmann H., Burlacu-Miron S., Craescu C.T., Mantsch H.H., Schultz C.P.

  The adk gene from Mycobacterium tuberculosis codes for an enzyme of 181 amino acids. A sequence comparison with 52 different forms of adenylate kinases (AK) suggests that the enzyme from M. tuberculosis belongs to a new subfamily of "short" bacterial AKs. The recombinant protein, overexpressed in ... >> More

  The adk gene from Mycobacterium tuberculosis codes for an enzyme of 181 amino acids. A sequence comparison with 52 different forms of adenylate kinases (AK) suggests that the enzyme from M. tuberculosis belongs to a new subfamily of "short" bacterial AKs. The recombinant protein, overexpressed in Escherichia coli, exhibits a low catalytic activity and an unexpectedly high thermal stability (Tm = 64.8 degrees C). Based on various spectroscopic data, on the known three-dimensional structure of the AK from E. coli and on secondary structure predictions for various sequenced AKs, we propose a structural model for AK from M. tuberculosis (AKmt). Proteins 1999;36:238-248. << Less

  Proteins 36:238-248(1999) [PubMed] [EuropePMC]

• The characterization of human adenylate kinases 7 and 8 demonstrates differences in kinetic parameters and structural organization among the family of adenylate kinase isoenzymes.

  Panayiotou C., Solaroli N., Xu Y., Johansson M., Karlsson A.

  Differences in expression profiles, substrate specificities, kinetic properties and subcellular localization among the AK (adenylate kinase) isoenzymes have been shown to be important for maintaining a proper adenine nucleotide composition for many different cell functions. In the present study, h ... >> More

  Differences in expression profiles, substrate specificities, kinetic properties and subcellular localization among the AK (adenylate kinase) isoenzymes have been shown to be important for maintaining a proper adenine nucleotide composition for many different cell functions. In the present study, human AK7 was characterized and its substrate specificity, kinetic properties and subcellular localization determined. In addition, a novel member of the human AK family, with two functional domains, was identified and characterized and assigned the name AK8. AK8 is the second known human AK with two complete and active AK domains within its polypeptide chain, a feature that has previously been shown for AK5. The full-length AK8, as well as its two domains AK8p1 and AK8p2, all showed similar AK enzyme activity. AK7, full-length AK8, AK8p1 and AK8p2 phosphorylated AMP, CMP, dAMP and dCMP with ATP as the phosphate donor, and also AMP, CMP and dCMP with GTP as the phosphate donor. Both AK7 and full-length AK8 showed highest affinity for AMP with ATP as the phosphate donor, and proved to be more efficient in AMP phosphorylation as compared with the major cytosolic isoform AK1. Expression of the proteins fused with green fluorescent protein demonstrated a cytosolic localization for both AK7 and AK8. << Less

  Biochem. J. 433:527-534(2011) [PubMed] [EuropePMC]

• Maize leaf adenylate kinase: purification and partial characterization.

  Kleczkowski L.A., Randall D.D.

  Adenylate kinase (EC 2.7.4.3) from leaves of maize (Zea mays) was purified to homogeneity using (NH(4))(2)SO(4) fractionation, followed by chromatography on DEAE-cellulose, hydroxyapatite, Sephadex G-75SF, and Green A dye-ligand columns. The purified enzyme had specific activity of about 1,550 mic ... >> More

  Adenylate kinase (EC 2.7.4.3) from leaves of maize (Zea mays) was purified to homogeneity using (NH(4))(2)SO(4) fractionation, followed by chromatography on DEAE-cellulose, hydroxyapatite, Sephadex G-75SF, and Green A dye-ligand columns. The purified enzyme had specific activity of about 1,550 micromoles ADP produced per minute per milligram protein, and the ratio of velocities of the reverse (utilization of ATP) to forward (formation of ATP) reaction was about 1.5. The M(r) value of adenylate kinase, determined by electrophoresis in dissociating conditions and by gel filtration, was 29,000 and 31,000 respectively, suggesting monomeric nature of the enzyme. Purified preparations were stable for at least 1 month at 0 to 4 degrees C. Magnesium ions were essential for activity of adenylate kinase in both directions of the reaction. Optimal rates in the forward direction were observed at the magnesium to ADP ratio of about 0.6 to 0.8. For the reverse reaction, ATP served as a substrate only when complexed with magnesium, while AMP reacted as a free species. The enzyme preferentially utilized adenine ribonucleotides in both directions of the reaction. The nucleoside triphosphate-binding site of adenylate kinase was fairly nonspecific with regard to nucleotide species. On the other hand, the primary amino group of either adenine and cytosine moieties was essential for effective binding to the nucleoside monophosphate site of the enzyme. << Less

  Plant Physiol. 81:1110-1114(1986) [PubMed] [EuropePMC]

• The crystal structure of human adenylate kinase 6: an adenylate kinase localized to the cell nucleus.

  Ren H., Wang L., Bennett M., Liang Y., Zheng X., Lu F., Li L., Nan J., Luo M., Eriksson S., Zhang C., Su X.-D.

  Adenylate kinases (AKs) play important roles in nucleotide metabolism in all organisms and in cellular energetics by means of phosphotransfer networks in eukaryotes. The crystal structure of a human AK named AK6 was determined by in-house sulfur single-wavelength anomalous dispersion phasing metho ... >> More

  Adenylate kinases (AKs) play important roles in nucleotide metabolism in all organisms and in cellular energetics by means of phosphotransfer networks in eukaryotes. The crystal structure of a human AK named AK6 was determined by in-house sulfur single-wavelength anomalous dispersion phasing methods and refined to 2.0-A resolution with a free R factor of 21.8%. Sequence analyses revealed that human AK6 belongs to a distinct subfamily of AKs present in all eukaryotic organisms sequenced so far. Enzymatic assays show that human AK6 has properties similar with other AKs, particularly with AK5. Fluorescence microscopy showed that human AK6 is localized predominantly to the nucleus of HeLa cells. The identification of a nuclear-localized AK sheds light on nucleotide metabolism in the nucleus and the energetic communication between mitochondria and nucleus by means of phosphotransfer networks. << Less

  Proc. Natl. Acad. Sci. U.S.A. 102:303-308(2005) [PubMed] [EuropePMC]

• Functions of chloroplastic adenylate kinases in Arabidopsis.

  Lange P.R., Geserick C., Tischendorf G., Zrenner R.

  Adenosine monophosphate kinase (AMK; adenylate kinase) catalyses the reversible formation of ADP by the transfer of one phosphate group from ATP to AMP, thus equilibrating adenylates. The Arabidopsis (Arabidopsis thaliana) genome contains 10 genes with an adenylate/cytidylate kinase signature; sev ... >> More

  Adenosine monophosphate kinase (AMK; adenylate kinase) catalyses the reversible formation of ADP by the transfer of one phosphate group from ATP to AMP, thus equilibrating adenylates. The Arabidopsis (Arabidopsis thaliana) genome contains 10 genes with an adenylate/cytidylate kinase signature; seven of these are identified as putative adenylate kinases. Encoded proteins of at least two members of this Arabidopsis adenylate kinase gene family are targeted to plastids. However, when the individual genes are disrupted, the phenotypes of both mutants are strikingly different. Although absence of AMK2 causes only 30% reduction of total adenylate kinase activity in leaves, there is loss of chloroplast integrity leading to small, pale-looking plantlets from embryo to seedling development. In contrast, no phenotype for disruption of the second plastid adenylate kinase was found. From this analysis, we conclude that AMK2 is the major activity for equilibration of adenylates and de novo synthesis of ADP in the plastid stroma. << Less

  Plant Physiol. 146:492-504(2008) [PubMed] [EuropePMC]

• The human adenylate kinase 9 is a nucleoside mono- and diphosphate kinase.

  Amiri M., Conserva F., Panayiotou C., Karlsson A., Solaroli N.

  Adenylate kinases regulate adenine nucleotide levels and are present in different intracellular compartments. These enzymes also participate in the activation of pharmacologically active nucleoside and nucleotide analogs. We have in the present study identified the ninth isoform of the adenylate k ... >> More

  Adenylate kinases regulate adenine nucleotide levels and are present in different intracellular compartments. These enzymes also participate in the activation of pharmacologically active nucleoside and nucleotide analogs. We have in the present study identified the ninth isoform of the adenylate kinase family of enzymes and accordingly named the protein adenylate kinase 9 (AK9). Initially a full-length cDNA of a hypothetical protein containing a predicted adenylate kinase domain was identified and subsequently cloned and expressed in Escherichia coli. The substrate specificity of the recombinant protein showed that the enzyme catalyzed the phosphorylation of AMP, dAMP, CMP and dCMP with ATP as phosphate donor, while only AMP and CMP were phosphorylated when GTP was the phosphate donor. The kinetic parameters of AK9 were determined for AMP, dAMP and CMP with ATP as phosphate donor. Interestingly, in addition to the diphosphate products, a nucleoside diphosphate kinase (NDPK) activity was also present with subsequent triphosphates formed. With ATP or GTP as phosphate donor it was possible to detect the production of ATP, CTP, GTP, UTP, dATP, dCTP, dGTP and TTP as enzymatic products from the corresponding diphosphate substrates. A number of previously characterized adenylate kinases were also tested and found to possess a broad phosphotransferase activity similar to AK9. These enzymes are accordingly suggested to be regarded as nucleoside mono- and diphosphate kinases with catalytic activities possibly determined by local substrate concentrations. << Less

  Int. J. Biochem. Cell Biol. 45:925-931(2013) [PubMed] [EuropePMC]

  This publication is cited by 23 other entries.

• Yeast adenylate kinase is active simultaneously in mitochondria and cytoplasm and is required for non-fermentative growth.

  Bandlow W., Strobel G., Zoglowek C., Oechsner U., Magdolen V.

  Displacement of the single copy structural gene for yeast adenylate kinase (long version) by a disrupted nonfunctional allele is tolerated in haploid cells. Since adenylate kinase activity is a pre-requisite for cell viability, the survival of haploid disruption mutants is indicative of the presen ... >> More

  Displacement of the single copy structural gene for yeast adenylate kinase (long version) by a disrupted nonfunctional allele is tolerated in haploid cells. Since adenylate kinase activity is a pre-requisite for cell viability, the survival of haploid disruption mutants is indicative of the presence of an adenylate kinase isozyme in yeast, capable of forming ADP from AMP and, thus, of complementing the disrupted allele. The phenotype of these disruption mutants is pet, showing that complementation occurs only under fermentative conditions. Even on glucose, growth of the disruption mutants is slow. Adenylate kinase activity is found both in mitochondria and cytoplasm of wild type yeast. The disruption completely destroys the activity in mitochondria, whereas in the cytoplasmic fraction about 10% is retained. An antibody raised against yeast mitochondrial adenylate kinase recognizes cross-reacting material both in mitochondria and cytoplasm of the wild type, but fails to do so in each of the respective mutant fractions. The data indicate that yeast adenylate kinase (long version, AKY2) simultaneously occurs and is active in mitochondria and cytoplasm of the wild type. Nevertheless, it lacks a cleavable pre-sequence for import into mitochondria. A second, minor isozyme, encoded by a separate gene, is present exclusively in the cytoplasm. << Less

  Eur. J. Biochem. 178:451-457(1988) [PubMed] [EuropePMC]